Abstract: A semiconductor device including a substrate; a gate structure on the substrate; a gate spacer on a sidewall of the gate structure; and a polishing stop pattern on the gate structure and the gate spacer, the polishing stop pattern including a first portion covering an upper surface of the gate structure and an upper surface of the gate spacer; and a second portion extending from the first portion in a vertical direction substantially perpendicular to an upper surface of the substrate, wherein an upper surface of a central portion of the first portion of the polishing stop pattern is higher than an upper surface of an edge portion of the first portion thereof, and the upper surface of the central portion of the first portion of the polishing stop pattern is substantially coplanar with an upper surface of the second portion thereof.

Abstract: A semiconductor device including a substrate; a gate structure on the substrate; a gate spacer on a sidewall of the gate structure; and a polishing stop pattern on the gate structure and the gate spacer, the polishing stop pattern including a first portion covering an upper surface of the gate structure and an upper surface of the gate spacer; and a second portion extending from the first portion in a vertical direction substantially perpendicular to an upper surface of the substrate, wherein an upper surface of a central portion of the first portion of the polishing stop pattern is higher than an upper surface of an edge portion of the first portion thereof, and the upper surface of the central portion of the first portion of the polishing stop pattern is substantially coplanar with an upper surface of the second portion thereof.

Abstract: An exhaust system may include an injector mounted at an exhaust pipe or an engine and additionally injecting fuel, a diesel fuel cracking catalyst mounted at the exhaust pipe downstream of the injector and converting additionally injected fuel into a high-reactivity reducing agent through thermal cracking, a DE-NOx catalyst mounted at the exhaust pipe downstream of the diesel fuel cracking catalyst, storing the nitrogen oxide contained in the exhaust gas, and releasing the stored nitrogen oxide by the additionally injected fuel so as to reduce the nitrogen oxide through oxidation-reduction reaction with the high-reactivity reducing agent, and a control portion controlling an additional injection of fuel according to driving condition of the engine, wherein the control portion may control the injector to additionally inject the fuel according to a predetermined injection pattern in a case that driving condition of the engine satisfies an additional injection condition of the fuel and an additional injection ti

Abstract: An exhaust system may include an injector mounted at an exhaust pipe or an engine and additionally injecting fuel, a diesel fuel cracking catalyst mounted at the exhaust pipe downstream of the injector and converting additionally injected fuel into a high-reactivity reducing agent through thermal cracking, a DE-NOx catalyst mounted at the exhaust pipe downstream of the diesel fuel cracking catalyst, storing the nitrogen oxide contained in the exhaust gas, and releasing the stored nitrogen oxide by the additionally injected fuel so as to reduce the nitrogen oxide through oxidation-reduction reaction with the high-reactivity reducing agent, and a control portion controlling an additional injection of fuel according to driving condition of the engine, wherein the control portion may control the injector to additionally inject the fuel according to a predetermined injection pattern in a case that driving condition of the engine satisfies an additional injection condition of the fuel and an additional injection ti